초록 ▼

A transistor is operated in the PWM mode such that a hlaf sine wave of current is delivered first to one-half of a distribution transformer and then the other as determined by steering thyristors operated at the fundamental sinusoidal frequency. Power to the transistor is supplied by a dc source suc

A transistor is operated in the PWM mode such that a hlaf sine wave of current is delivered first to one-half of a distribution transformer and then the other as determined by steering thyristors operated at the fundamental sinusoidal frequency. Power to the transistor is supplied by a dc source such as a solar array and the power is converted such that a sinusoidal current is injected into a utility at near unity power factor.

대표청구항 ▼

A dc-to-ac inverter for injecting a sinusoidal current waveform into an ac utility grid from a dc source comprising: gate controllable chopping switch means in series with said dc source; at least two steering switch means for connecting said gate controllable switch means to opposite sides of said

A dc-to-ac inverter for injecting a sinusoidal current waveform into an ac utility grid from a dc source comprising: gate controllable chopping switch means in series with said dc source; at least two steering switch means for connecting said gate controllable switch means to opposite sides of said load; means for alternately gating said two steering switch means at the fundamental frequency of the desired sinusoidal waveform to alternately provide current flow in a first direction through said load and a second direction opposite to the first; and means for pulse width modulating the gate controllable switch means to achieve sinusoidal current delivered to said utility grid at near unity power factor, said pulse width modulating means having means for sensing current supplied to said utility grid, means for generating a sinusoidal current reference waveform, and comparator means having hysteresis for comparing current supplied to said utility grid to said sinusoidal current reference waveform, and supplying switching pulses to said gate controllable switching means to confine the current supplied to the utility grid to a predetermined band about said sinusoidal current reference waveform.